Time delay actuator for mercury relay



United States Patent 3,187,142 TIME DELAY ACTUATQR EQR MERCURY RELAY George H. Elenhaas, Ellrhart, Ind, assignor to Durairool, Inc., Elkhart, Inch, a corporation of Indiana Filed Apr. 4, 1963, Ser. No. 276,740 Claims. (Cl. 200-97) My present invention relates generally to a mercury relay assembly and more specifically to a mercury relay and an associated time delay actuator therefor.

In the embodiment of my invention herein disclosed I have shown and described a normally open type relay comprising a casing which supports a first body of mercury therein and serves as one electrode for the relay. An electrode member mounted in insulated relation in the casing serves as a second electrode for the relay. Disposed in the casing is plunger means normally in floating relation in the first body of mercury. The plunger means comprises a metal sleeve member, and a member of insulating material disposed internally of the sleeve member and having a cup-shaped portion for supporting a second body of mercury in insulated relation with respect to the first body of mercury and in contacting engagement with the second electrode.

It is an object of my present invention to provide a mercury relay of the general class described and a time delay actuator therefor which is adapted to attract the relay plunger means into the first body of mercury for efiecting engagement thereof with the second body of mercury to establish a circuit between the two relay electrodes.

It is another object of my present invention to provide a mercury relay assembly, as described, wherein the time delay actuator comprises a metal casing having hollow plunger means movable in a viscous fiuid within the easing, and coil means adapted when energized to attract the hollow plunger means in the direction of the coil means whereby the magnetic flux intensity in the hollow plunger means is increased for attracting the relay plunger means into the first body of mercury.

It is a further object of my present invention to provide a mercury relay assembly, as described, wherein the hollow plunger means of the actuator has metering means through which the viscous fluid in the actuator casing must flow thus effecting a time delay in the movement of the hollow plunger means in the direction of the coil means whereby the attraction of the relay plunger means into the first body of mercury following energization of the coil means is delayed.

As a feature of the preferred embodiment of my present invention disclosed herein, the hollow plunger means of the actuator is provided with valve means that opens when the hollow plunger means is moving in a direction away from the coil means for permitting movement in such direction at a relatively rapid rate.

It is a still further object of my present invention to provide a mercury relay assembly, as described, wherein spring means is arranged within the actuator casing for biasing the hollow plunger means of the actuator in a direction away from the coil means when the latter is deenergized.

Now in order to acquaint those skilled in the art with the manner of constructing and using mercury relay assemblies in accordance with the principles of my present invention, I shall describe in connection with the accompanying drawing, a preferred embodiment of my invention.

In the drawing:

FIGURE 1 is a detail vertical sectional view through a relay assembly constructed in accordance with the principles of my present invention with the relay being shown in its normal open position;

FIGURE 2 is a detail vertical sectional view of the relay assembly of FIGURE 1 showing it in its closed position; and

FEGURE 3 is a sectional view of the relay assembly of FIGURE 2, taken substantially along the line 3-3 in FIGURE 2, looking in the direction indicated by the arrows.

Referring now to FIGURE 1, I have shown a relay, indicated generally by the reference numeral 10, and a relay actuator, indicated generally by the reference numeral 11.

The relay It) comprises a non-magnetic metal casing or shell 12 formed of a cylindrical tube of stainless steel or other suitable metal having a closed lower end wall 13 and an upper radially extending annular flange portion 14. In the embodiment of my invention herein disclosed the casing 12 serves as one electrode or terminal for the relay It). An electrode member 15, which serves as a second electrode or terminal for the relay 10, extends inwardly of the upper end of the casing 12. The electrode 15 may be of any suitable form and, as shown, is embedded in a glass or ceramic annulus 16 carried in and fused to the inner surface of the tubular portion of a cap member 17 having a radially extending annular flange portion 13 suitably secured, as by welding, to the casing flange Ltd. This arrangement provides for an insulated, and preferably gas-tight, mounting of the electrode 15 within the casing 12, which mounting also serves to pre vent mercury from escaping from the interior of the easing 12. The electrode 15 may be made of molybdenum or other suitable arc resisting metal, and the cap member 17 may be formed of stainless steel or comparable metal, as required to accommodate expansion of the glass or ceramic annulus 16.

As previously related, the casing 12 is preferably of cylindrical shape and is of suitable dimensions for receiving a substantially cylindrical plunger or displacer means 19. The plunger 19 comprises a substantially cylindrical magnetic metal sleeve member 20 open at its upper and lower ends and having radially outwardly projecting protuberances 21 which have guiding engagement with the internal cylindrical surface of the casing 12 in the vertical movement of the plunger 19. The plunger 19 further comprises a cylindrical magnetic liner member 22 which is substantially axially coextensive with the sleeve member Zil, and a bumper disc 23 mounted within the lower end of the sleeve 2%. Disposed internally of the liner 22 is an arc shield means formed by an upper hollow ceramic member 24, an intermediate annular ceramic member 25, and a lower ceramic member 26 having an upwardly projecting hollow cup portion 27 coaxially received in the intermediate ceramic member 25. An annular spacer ring 23 is provided between the lower end of the ceramic member 26 and the bumper disc 23. The upper and lower ends of the sleeve 29 are turned radially inwardly, respectively at 29 and 3%), to hold the ceramic members, spacer ring and bumper disc in assembled relation.

While the ceramic member 26 is shown in cross section, it is to be understood that this member contains suitable axial ports or passageways 31 permitting the passage of mercury upwardly through the interior of the liner 22 so that the same may enter the bore of the hollow cup portion 27 of the ceramic member 215. The flow of mercury into and out of the interior of the plunger 19 is regulated or controlled by ports 32 formed through the bumper disc 23. The plunger means 19 constructed as above described has normal floating relation in a main or first body of mercury 33 contained in the lower end portion of the casing 12. A second body of mercury 34 is contained or supported in the bore of the cup portion 27 of the ceramic member 26 and receives the inner end portion of the electrode 15. With the plunger means 19 in its normal floating position shown in FIGURE 1, the main body of mercury 33 is out of contact with the second body of mercury 34 and the relay it is in normally open position.

Axially aligned with the relay lid is the relay actuator II which comprises a metal casing 35 formed of a cylindrical tube of stainless steel or other suitable metal having a closed upper end wall as abutting the lower end wall i3 of the plunger casing 12. The two casings I2 and 35, if desired, may be maintained in the position shown by means of a common mounting collar or bracket member (not shown). Disposed for axial movement within the casing 35 is a generally hollow plunger 37, of a ferromagnetic material, open at its lower end and having a head portion 38 with a central axial bore 39 therein.

Mounted at the lower end of the plunger 37 is time delay means dtl which may, for example, comprise a timing disc 41 suitably secured about its periphery toaxial mounting pins 42 integral with the plunger 37. The timing disc ill has an upstanding central frusto-conical formation 43 which defines a valve opening 44 and in which are formed one or more metering orifices d5. Normally supported by the timing disc 41 within the valve opening 44 is a ball valve as formed of non-magnetic steel. Suitably secured, as by welding, to the ball valve 45 below the timing disc dll is a limit plate 47 which, as shown in FIG- URE 3, is preferably Y-shaped. The plate 47 limits the permissible axial movement of the ball valve 46 relative to the valve opening Fastened within the casing adjacent the lower end thereof is an annular spring retainer 43. A tension coil spring 49, which is secured at its upper end to the lower end of the plunger 37 and at its lower end to the spring retainer 48, serves to maintain the plunger 37 normally in the downward position shown in FIGURE 1. A standard closure or seal member 56*, through which fluid may be introduced into the casing 35, is disposed in the lower end of casing 35. T 0 control axial movement of the plunger 37, the casing 35 is preferably filled with a silicon fluid or other suitable viscous fluid 51. The relay actuator 11 further comprises an energizing coil means 52 carried in a suitable supporting bracket 53 surrounding the upper end of the actuator casing 35.

The operation of the above described time delay relay of my present invention is as follows:

When the coil means 52 is de-ener ized, the relay actuator plunger 37 is held in the position shown in FIG- URE 1 by the tension spring 49, and the relay plunger 19 remains in its normal floating position shown in FIG- URE 1. At this time, the relay in is in normal open position with the electrode 15 and the body of mercury 34 in the cup portion 2'] being maintained out of contact with the main body of mercury 33 in the lower end of the relay casing I2.

Upon energization of the energizing coil means 52, the actuator plunger 37 is attracted upwardly to the position shown in FIGURE 2. Such upward movement of the plunger 37 takes place at a slow rate because the ball valve 4% is seated within the valve opening 44 and the silicon fluid 51 being displaced by the plunger 37 must pass through the metering orifices in the timing disc 41. As the plunger 37 moves upwardly within the coil means 52., the magnetic flux in the head portion 38 thereof intensifies and the relay plunger 19 is thereby attracted downwardly from the position shown in FIGURE 1 to the position shown in FIGURE 2. This downward move ment of the relay plunger 19 causes the mercury 33 to flow through the ports 32 in the bumper disc 23, the interior of the plunger 19 and the passageways 3i, and places the main body of mercury 33 in communication with the second body of mercury and the electrode I5 to complete a circuit through the relay. It will be appreciated that due to the time delay in the upward movement of the actuator plunger 37 the attraction of the relay plunger 19 into the main body of mercury 33 following energization of the coil means 52 is delayed.

N ow with the relay Ill in its closed position as shown in FIGURE 2 and upon de-energization of the coil means 52, the relay actuator plunger 37 will be returned by the tension spring 4-9 to its normal position shown in FIG- URE 1. At the start of the downward movement of the plunger 57, the ball valve 46 will be forced away from the valve seat formed by the valve opening 44 in the disc ill. Movement of the ball valve 46 relative to the valve opening is limited by engagement of the plate 47 with the underside of the disc 41. When the ball valve as is unseated, the silicon fiuid SI being displaced by the plunger 37 is permitted to pass through the valve opening 44 as well as the metering orifices 45 whereby a relatively rapid return of the plunger 37 to its normal position is effected. At the time that the coil means 52 is tie-energized, the magnetic force imposed on the relay plunger 1% rapidly diminishes and the latter is permitted to return upwardly to its normal floating position. As the relay plunger 1% moves upwardly, the mercury will flow through the passageways 31, the interior of the plunger 19 and the bumper disc ports 32 to efiect rapid return of the main body of mercury 33 to its normal position in the lower end of the casing 12. In this manner, rapid separation of the two bodies of mercury 33 and 34 is effected to produce quick breaking of a circuit through the relay lt After the coil means 52 has been tie-energized for a limited period of time the ball valve 4 6 will again seat on the valve seat formed by the valve opening 44 in the disc 41, as shown in FIGURE 1, so that upon energization of the coil 52 delayed or slow making of a circuit through the relay It) as first above described will be effected.

The above described relay actuator plunger 37 moves upwardly at a slow rate and downwardly at a relatively rapid rate, thus having slow operate and rapid release characteristics. Should it be desired to have the relay actuator plunger 37 move both upwardly and downwardly at a slow rate, a simple pierced disc may be substituted for the time delay mean-s dd. Under these circumstances, the plunger 37 would have slow operate and slow release characteristics. 1

While I have shown and described what I believe to be a preferred embodiment of my present invention it will be understood by those skilled in the art that various modificatlons and rearrangements may be made therein without departing from the spirit and scope of my invention.

Iclaim:

l. A mercury relay assembly comprising a pair of electrode means insulated from each other with one of said electrode means having contacting engagement with a first body of mercury for said relay and the other of said electrode means having contacting engagement with a second body of mercury for said relay, first plunger means adapted in a first operative position to maintain said two bodies of mercury out of contact and in a second operative position to maintain said two bodies of mercury in contact to establish a circuit between said pair of electrode means, second plunger means, and coil means adapted when energized to attract said second plunger means in.

he direction of said coil means whereby the magnetic flux intensity in said second plunger means is increased and said first plunger means is attracted thereby and moved toward said second plunger means from one oper ative position to the other operative position.

2. A mercury relay assembly comprising a pair of electrode means insulated from each other with one of said electrode means having contacting engagement with a first body of mercury for said relay and the other of said electrode means having contacting engagement with a second body of mercury for said relay, first plunger means adapted in a first operative position to maintain said two bodies of mercury out of contact and in a second operative position to maintain said two bodies of mercury in contact to establish a circuit between said pair of electrode means, second hollow plunger means movable in a viscous fluid, coil means adapted when energized to attract said second plunger means within said coil means whereby the magnetic flux intensity in said second plunger means is increased and said first plunger means is attracted thereby and moved from one operative position to the other operative position, and said second plunger means having metering means through which said viscous fluid must flow for effecting a time delay in the movement of said second plunger means within said coil means.

3. A mercury relay assembly comprising a pair of electrode means insulated from each other with one of said electrode means having contacting engagement with a first body of mercury for said relay and the other of said electrode means having contacting engagement with a second body of mercury for said relay, first plunger means adapted in a first operative position to maintain said two bodies of mercury out of contact and in a second operative position to maintain said two bodies of mercury in contact to establish a circuit between said said pair of electrode means, second hollow plunger means movable in a viscous fluid between two operative positions, spring means normally maintaining said second plunger means in one operative position, coil means adapted when energized to attract said second plunger means to its second operative position whereby the magnetic flux intensity in said second plunger means is increased and said first plunger means is attracted thereby and moved from one operative position to the other operative position, and said second plunger means having metering means through which said viscous fluid must flow for effecting a time delay in the movement of said second plunger means to its second operative position.

4. A mercury relay assembly comprising a pair of electrode means insulated from each other with one of said electrode means having contacting engagement with a first body of mercury for said relay, first plunger means adapted to be normally supported in floating relation in said first body of mercury for supporting a second body of mercury in insulated relation with respect to said first body of mercury and in contacting engagement with the other of said electrode means, second plunger means, and coil means adapted when energized to attract said second plunger means in the direction of said coil means whereby the magnetic flux intensity in said second plunger means is increased and said first plunger means is attracted thereby toward said second plunger means into said first body of mercury effecting engagement thereof with said second body of mercury to establish a circuit between said pair of electrode means.

5. A mercury relay assembly comprising a pair of electrode means insulated from each other with one of said electrode means having contacting engagement with a first body of mercury for said relay, first plunger means adapted to be normally supported in floating relation in said first body of mercury for supporting a second body of mercury in insulated relation with respect to said first body of mercury and in contacting engagement with the other of said electrode means, second hollow plunger means movable in a viscous fluid, coil means adapted when energized to attract said second plunger means within said coil means whereby the magnetic flux intensity in said second plunger means is increased and said first plunger means is attracted thereby into said first body of mercury effecting engagement thereof with said second body of mercury to establish a circuit between said pair of electrode means, and said second plunger means having metering means through which said viscous fluid must flow for effecting a time delay in the movement of said second plunger means within said coil means.

6. A mercury relay assembly comprising a first metal casing for supporting a first body of mercury therein and adapted to serve as one electrode for the relay, an electrode member mounted in insulated relation in said first casing and serving as a second electrode for said relay, first plunger means disposed in said first casing normally in floating relation in said first body of mercury comprising a metal sleeve member and a member of insulating material disposed internally of said sleeve member having a cup-shaped portion for supporting a second body of mercury in insulated relation with respect to said first body of mercury and in contacting engagement with said second electrode, a second metal casing adjacent said first metal casing and having second plunger means movable therein, and coil means adapted when energized to attract said second plunger means in the direction of said coil means and said first casing whereby the magnetic flux intensity in said second plunger means is increased and said first plunger means is attracted thereby toward said second plunger means into said first body of mercury effecting engagement thereof with said second body of mercury to establish a circuit between said two electrodes.

7. A mercury relay assembly comprising a first metal casing for supporting a first body of mercury therein and adapted to serve as one electrode for the relay, an electrode member mounted in insulated relation. in said first casing and serving as a second electrode for said relay, first plunger means disposed in said first casing normally in floating relation in said first body of mercury comprising a metal sleeve member and a member of insulating material disposed internally of said sleeve member having a cup-shaped portion for supporting a second body of mercury in insulated relation with respect to said first body of mercury and in contacting engagement with said second electrode, a second metal casing adjacent said first metal casing and having second hollow plunger means movable therein, said second casing being filled with a viscous fluid, coil means adapted when energized to attract said second plunger means in the direction of said coil means and said first casing whereby the magnetic flux intensity in said second plunger means is increased and said first plunger means is attracted thereby into said first body of mercury effecting engagement thereof with said second body of mercury to establish a circuit between said two electrodes, said second plunger means having metering means through which said viscous fluid means flow for effecting a time delay in the movement of said second plunger means in the direction of said coil means, and spring means biasing said second plunger means in a direction away from said coil means and said first casing when said coil means is de-energized.

8. An actuator assembly for a mercury relay comprising hollow plunger means completely submerged and movable in a viscous fluid, coil means adapted when energized to attract said plunger means in the direction of said coil means whereby the magnetic flux intensity in said plunger means is increased for effecting magnetic actuation of the mercury relay, and said plunger means having metering means through which said viscous fluid must flow for effecting a time delay in the movement of said plunger means in the direction of said coil means.

9. An actuator assembly for a mercury relay comprising a metal casing having hollow plunger means movable therein, said casing being filled with a viscous fluid, coil means adapted when energized to attract said plunger means in the direction of said coil means whereby the magnetic fluX intensity in said plunger means is increased for effecting magnetic actuation of the mercury relay, said plunger means having metering means through which said viscous fluid must flow for effecting a time delay in the movement of said plunger means in the direction or" said coil means, and spring means within said casing for biasing said plunger means in a direction away from said coil means when the latter is de-energized.

10. An actuator assembly for a mercury relay comprising a metal casing having hollow plunger means enemas movable therein, said casing being filled with a viscous fluid, coil means adapted when energized to attract said plunger means in the direction of said coil means whereby the magnetic flux intensity in said plunger means is increased for effecting magnetic actuation of the mercury relay, said plunger means having metering means through which said viscous fluid must flow for eiiecting a time delay in the movement of said plunger means in the direction of said coil means, said plunger means having valve means which opens when said plunger means is moving in a direction away from said coil means for permitting movement in such direction at a relatively rapid rate,

and spring means within said casing for biasing said plunger means in a direction away from said coil means when the latter is de-energized.

BERNARD A. GILHEANY, Primary Examiner. RGBERT K. SCHAEFER, Examiner. 

2. A MERCURY RELAY ASSEMBLY COMPRISING A PAIR OF ELECTRODE MEANS INSULATED FROM EACH OTHER WITH ONE OF SAID ELECTRODE MEANS HAVING CONTACTING ENGAGEMENT WITH A FIRST BODY OF MERCURY OF SAID RELAY AND THE OTHER OF SAID ELECTRODE MEANS HAVING CONTACTING ENGAGEMENT WITH A SECOND BODY OF MERCURY FOR SAID RELAY, FIRST PLUNGER MEANS ADAPTED IN A FIRST OPERATIVE POSITION TO MAINTAIN SAID TWO BODIES OF MERCURY OUT OF CONTACT AND IN A SECOND OPERATIVE POSITION TO MAINTAIN SAID TWO BODIES OF MERCURY IN CONTACT TO ESTABLISH A CIRCUIT BETWEEN SAID PAIR OF ELECTRODE MEANS, SECOND HOLLOW PLUNGER MEANS MOVABLE IN A VISCOUS FLUID, COIL MEANS ADAPTED WHEN ENERGIZED TO ATTRACT SAID SECOND PLUNGER MEANS WITHIN SAID COIL MEANS WHEREBY THE MAGNETIC FLUX INTENSITY IN SAID SECOND PLUNGER MEANS IS INCREASED AND SAID FIRST PLUNGER MEANS IS ATTRACTED THEREBY AND MOVED FROM ONE OPERATIVE POSITION TO THE OTHER OPERATIVE POSITION, AND SAID SECOND PLUNGER MEANS HAVING METERING MEANS THROUGH WHICH SAID VISCOUS FLUID MUST FLOW FOR EFFECTING A TIME DELAY IN THE MOVEMENT OF SAID SECOND PLUNGER MEANS WITHIN SAID COIL MEANS. 